Method for transmitting downlink control messages in cellular system

ABSTRACT

A method for transmitting control messages is disclosed. The method includes grouping a plurality of control messages for at least one user equipment based on at least one criteria of whether or not uplink ACK/NACK channel indexes are allowed to be implicitly used in the control messages, whether or not the user equipment corresponding to the control messages is able to implicitly use the uplink ACK/NACK channel indexes, sizes of Information Elements (IEs) of the control messages, whether or not the control messages are segmented into a predetermined number of subblocks, MCS levels applied to the control messages, sizes of allocated IEs of the control messages after applying the MCS levels, and frequency partitions in which the IEs of the control messages are present, and transmitting the grouped control messages. The control messages included in each of the groups generated by grouping are equal in at said least one criteria.

This application claims the benefit of Korean Patent Application No.10-2009-0067915, filed on Jul. 24, 2009, which is hereby incorporated byreference as if fully set forth herein.

This application also claims the benefit of U.S. Provisional ApplicationSer. Nos. 61/108,559, filed on Oct. 27, 2008, 61/139,619, filed on Dec.21, 2008, 61/139,635, filed on Dec. 22, 2008, 61/149,024, filed on Feb.2, 2009, 61/149,708, filed on Feb. 4, 2009, 61/157,555, filed on Mar. 5,2009, 61/168,223, filed on Apr. 10, 2009, 61/181,672 filed on May 28,2009 and 61/220,584, filed on Jun. 26, 2009 the contents of which arehereby incorporated by reference herein in their entirety.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a method for reducing complexity indetection of control messages received by a user equipment, when thecontrol messages are transmitted to a user equipment or a user equipmentgroup in a cellular system.

2. Discussion of the Related Art

In a cellular system, in order to allow user equipments (UEs) to receivedata from a base station, the UEs should first transmit a variety ofinformation messages (hereinafter, control messages) such as resourcelocations, in which their data is present, modulation and coding schemesand Multiple-Input Multiple-Output (MIMO) schemes. Such control messagesshould be present in each of the UEs which will receive the data fromthe base station. Similarly, a method for grouping a plurality of UEsinto groups and transmitting control messages according to the groupsmay be considered. At this time, the size of each of the controlmessages may be changed according to the contents of information and themodulation and coding schemes.

Meanwhile, when a base station transmits control messages havingdifferent sizes to UEs, a method for reporting the location informationof the control messages in a frame and modulation and coding informationin advance and a method which does not report the above information maybe considered, respectively.

In the former case, since the UEs know the location of the controlmessages in the frame and the modulation and coding information, thecontrol messages can be easily detected. However, it is disadvantageousthat additional information should be further transmitted.

In contrast, in the latter case, since additional information is nottransmitted, overhead does not occur, but each of the UEs should performblind detection in order to confirm its control messages. That is, allthe UEs should perform blind detection with respect to all portions ofthe frame, in which the control messages are present. Meanwhile, if thenumber of cases which should be considered when the blind detection isperformed is increased, the complexity and time for confirming thecontrol messages are increased and thus the power of each of the UEs maybe lost. Accordingly, a method for easily performing blind detectionwhile minimizing overhead should be considered.

The complexity of the blind detection is changed depending on how largecontrol messages are constructed or how many control messages areconsidered. If all the sizes of the control messages are different fromone another, the complexity may be increased. Accordingly, the number ofsizes of the control messages is generally limited to a predeterminedvalue. For example, if a total of three sizes including 30 bits, 60 bitsand 90 bits are allowed as the sizes of the control messages, thecomplexity may be decreased. If the basic unit of the size is defined asa Control Block (CB) for convenience, control messages having threesizes of 1CB, 2CB and 3CB may be present (if it is assumed that 1CB=30bits).

However, even when the sizes of the control messages are set in the CBunits, the complexity of blind detection is significantly high. Forexample, if three types of CBs are present and a total of four controlmessages are considered, in blind detection, three cases (1CB, 2CB and3CB) are present when the number of control messages is 1, 3² cases arepresent when the number of control messages is 2, 3³ cases are presentwhen the number of control messages is 3, and 3⁴ cases are present whenthe number of control messages is 4.

If a total of 120 cases are present and a UE does not have informationabout the cases, the UE should perform detection a maximum of 120 timesin order to confirm whether the control messages of the UE are presentand which information is included if the control messages are present.In general, if the number of types of CBs is N and the maximum number ofcontrol messages is M, a maximum number of times of performing detectionis sum (N^(m)). Since the number of times of performing detectiondeteriorates system performance, a method for reducing the number oftimes of performing detection should be considered.

Meanwhile, frequency reuse is one method for increasing the number ofchannels per unit area in a cellular system. As a distance is increased,the intensity of a wave gradually weakens. Thus, interference betweenwaves is low at places separated from each other by a predetermineddistance or more, and thus the same frequency channel may be used. Usingsuch a principle, the same frequency may be simultaneously used invarious places such that subscriber capacity is significantly increased.The effective use of the frequency is called frequency reuse. A unit fordistinguishing between places is called a cell (mobile communicationcell) and frequency channel switch between cells for holding a call iscalled handoff. In an analog cellular mobile communication scheme,frequency reuse technology is necessary. A frequency reuse rate is oneparameter indicating frequency efficiency in a cellular system. Thefrequency reuse rate is obtained by dividing a total number of cells(sectors) simultaneously using the same frequency in a multi-cellstructure by a total number of cells (sectors) of the overall multi-cellstructure.

The frequency reuse rate of a 1G system (e.g., an Advanced Mobile PhoneSystem (AMPS)) is less than 1. For example, in 7-cell frequency reuse, afrequency reuse rate is 1/7. The frequency reuse rate of a 2G system(e.g., a Code Division Multiple Access (CDMA) or Time Division MultipleAccess (TDMA) system) is better than that of the 1G system. For example,the frequency reuse rate of a Global System for Mobile communication(GSM) which is a combination of a Frequency Division Multiplexing Access(FDMA) system and a TDMA may reach ¼ to ⅓. The frequency reuse rate of a2G CDMA system and a 3G WCDMA system may reach 1 such that spectralefficiency is increased and network arrangement costs are decreased.

When all the sectors of one cell and all the cells of one network usethe same frequency, a frequency reuse rate of 1 can be obtained.However, when the frequency reuse rate of 1 is obtained in a cellularnetwork, signal reception performance of UEs located on the boundarybetween cells is decreased by interference from a neighbor cell.

In an Orthogonal Frequency Division Multiple Access (OFDMA) system,since channels are separated in the subchannel units, a signal istransmitted via a subchannel and all channels are not used as in the 3Gsystem (CDMA2000 or WCDMA). Using such features, the throughput of theUEs located at the central area of a cell and the UEs located on theboundary between cells can be simultaneously improved. In detail, thecentral area of a cell is close to a base station and thus is safe fromco-channel interference from a neighbor cell. Accordingly, the UEslocated on the central area of a cell may use all available subchannels.However, the UEs located on the boundary between cells may use only someof all available subchannels. In the boundary between neighbor cells, afrequency is allocated such that the cells use different subchannels.Such a scheme is called Fractional Frequency Reuse (FFR).

If FFR is applied to a cellular system and the number of casesconsidered when blind detection is performed is increased, thecomplexity and time for confirming control messages are increased andthus the power of a UE is lost. Accordingly, there is a need for amethod for easily performing blind detection while minimizing overhead.

SUMMARY OF THE INVENTION

Accordingly, the present invention is directed to a method fortransmitting downlink control messages in a cellular system thatsubstantially obviates one or more problems due to limitations anddisadvantages of the related art.

An object of the present invention is to provide a method for easilyperforming blind detection of control messages transmitted from a basestation to a User Equipment (UE) while minimizing overhead.

Additional advantages, objects, and features of the invention will beset forth in part in the description which follows and in part willbecome apparent to those having ordinary skill in the art uponexamination of the following or may be learned from practice of theinvention. The objectives and other advantages of the invention may berealized and attained by the structure particularly pointed out in thewritten description and claims hereof as well as the appended drawings.

To achieve these objects and other advantages and in accordance with thepurpose of the invention, as embodied and broadly described herein, amethod for transmitting control messages from a base station to a userequipment in a cellular system includes, at the base station, grouping aplurality of control messages for at least one user equipment based onat least one criteria of whether or not uplink Acknowledgment/NegativeAcknowledgement (ACK/NACK) channel indexes are allowed to be implicitlyused in the control messages, whether or not the user equipmentcorresponding to the control messages is able to implicitly use theuplink ACK/NACK channel indexes, sizes of Information Elements (IEs) ofthe control messages, whether or not the control messages are segmentedinto a predetermined number of subblocks, Modulation and Coding Scheme(MCS) levels applied to the control messages, sizes of allocated IEs ofthe control messages after applying the MCS levels, and frequencypartitions in which the IEs of the control messages are present; andtransmitting the grouped control messages, wherein the control messagesincluded in each of the groups generated by grouping are equal in the atleast one criteria.

Each of the groups may include resource units which are logicallycontiguous or physically contiguous.

Information about the number of control messages included in each of thegroups or the size of each of the groups may be transmitted via anon-user-specific control message.

In each of the groups, the control messages included in each of thegroups may be transmitted in a state of being aligned based on the atleast one criteria.

Fractional Frequency Reuse (FFR) may be applied to a system, and theplurality of control messages may be present in at least one FrequencyPartition (FP) due to the FFR.

The MCS levels may be separately set for the at least one FP.

The same MCS level may be set with respect to the at least one FP.

The control messages may be present only in a predetermined FP.

The control messages may be positioned in the at least one FP.

According to the present invention, it is possible to easily performblind detection while minimizing overhead, by aligning and transmittingcontrol messages in a predetermined rule and informing a user ofinformation about a control message alignment pattern in advance beforetransmitting control messages. Accordingly, it is possible to reducecomplexity and time for confirming the control messages.

It is to be understood that both the foregoing general description andthe following detailed description of the present invention areexemplary and explanatory and are intended to provide furtherexplanation of the invention as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are included to provide a furtherunderstanding of the invention and are incorporated in and constitute apart of this application, illustrate embodiment(s) of the invention andtogether with the description serve to explain the principle of theinvention. In the drawings:

FIG. 1 is a construction diagram of a transmission resource fortransmitting control messages;

FIG. 2 is a view showing an example of generating control messageconstruction information;

FIG. 3 is a view showing examples of patterns of control messageconstruction information according to the present invention;

FIG. 4 is a view showing an example of control message constructioninformation for decreasing effective number of transmission bits ofcontrol message construction information;

FIG. 5 is a view showing a control message alignment pattern accordingto an embodiment of the present invention;

FIG. 6 is a view showing a control message alignment pattern accordingto an embodiment of the present invention;

FIG. 7 is a view showing a control message alignment pattern accordingto an embodiment of the present invention;

FIG. 8 is a view showing a control message alignment pattern accordingto an embodiment of the present invention;

FIGS. 9 to 13 are views showing control message alignment patterns ifFractional Frequency Reuse (FFR) is applied, according to an embodimentof the present invention; and

FIG. 14 is a block diagram showing the construction of a device which isapplicable to a base station and a User Equipment (UE) and is able toperform the above-described methods.

DETAILED DESCRIPTION OF THE INVENTION

The following embodiments are proposed by combining constituentcomponents and characteristics of the present invention according to apredetermined format. The individual constituent components orcharacteristics should be considered to be optional factors on thecondition that there is no additional remark. If required, theindividual constituent components or characteristics may not be combinedwith other components or characteristics. Also, some constituentcomponents and/or characteristics may be combined to implement theembodiments of the present invention. The order of operations to bedisclosed in the embodiments of the present invention may be changed.Some components or characteristics of any embodiment may also beincluded in other embodiments, or may be replaced with those of theother embodiments as necessary.

In the description of the drawings, procedures or steps which render thescope of the present invention unnecessarily ambiguous are not describedand procedures or steps which can be understood by those skilled in theart are not described.

The specific terms used in the following description are provided forfacilitating the understanding of the present invention and the use ofsuch specific terms may be modified without departing from the technicalscope of the present invention.

A whole band used by a base station is divided into a predeterminednumber of subbands. The whole band may be divided by a base station inadvance if Fractional Frequency Reuse (FFR) is used or may be dividedfor convenience of transmission of control messages. Accordingly, thenumber of subbands generated by dividing the whole band may be one ormore and the sizes of the subbands may be set to be equal or different.If a resource area for allowing a User Equipment (UE) to receive data isallocated in the subbands, the control messages of the UE are present inthe subbands.

The complexity of blind detection is changed depending on how largecontrol messages are constructed or how many control messages areconsidered. If all the sizes of the control messages are different, thecomplexity may be increased. Accordingly, the number of sizes of thecontrol messages is generally limited to a predetermined value. Forexample, if a total of three sizes including 30 bits, 60 bits and 90bits are allowed as the sizes of the control messages, complexity may besignificantly decreased. If the basic unit of the size is defined as aControl Block (CB) for convenience, control messages having three sizesof 1CB, 2CB and 3CB may be present.

Meanwhile, after control messages allocated to the resource area arecollected, a base station may align the control messages in descendingorder of the size thereof and sequentially transmit the controlmessages. For example, if four control messages respectively have sizesof 2CB, 1CB, 3CB and 3CB, the control messages are aligned in order of3CB, 3CB, 2CB and 1CB so as to be transmitted.

FIG. 1 is a construction diagram of a transmission resource fortransmitting control messages. As shown in FIG. 1, for convenience, itis assumed that the sizes of the control messages are integral multiples(e.g., 1CB, 2CB, 3CB and the like) of a Control Block (CB) and the sizeof a largest control message is NCB. It is assumed that a resourcehaving a total size of MCB within a divided band may be allocated fortransmission of control messages.

Accordingly, if the sizes of all messages are 1CB, a maximum of Mcontrol messages may be transmitted in the divided band. Fortransmission of control messages, if control messages having sizes of 1to NCB are combined and transmitted in a band to which a resource havinga size of MCB is allocated, various combinations are present. Incontrast, if control messages are aligned in descending order and aretransmitted from a base station, the number of cases is limited and thepattern thereof is also limited.

The cases where the size of a largest control message in the dividedband is 1CB to NCB may be considered. If it is assumed that the size ofa largest control message is n (1≦n≦N) CB, control messages having sizesof 1 to nCB are actually present and may be aligned in descending orderso as to be transmitted. In the present invention, when informationabout a pattern in which the control messages are aligned is controlmessage construction information, a base station transmits the controlmessage construction information in advance before the control messagesare transmitted.

Hereinafter, a method for constructing control message constructioninformation according to a first embodiment of the present inventionwill be described.

At this time, it is assumed that control message information is presentin all divided bands having a size of MCB in order to construct controlmessage construction information. That is, it is assumed that, if thesizes of all the control messages are less than MCB, control messageseach having a size of 1CB are present in the remaining portion. FIG. 2is a view showing an example of generating control message constructioninformation. For example, if M=12, n=3, and both the number of controlmessages having a size of 3CB and the number of control messages havinga size of 2CB are one, the example of generating constructioninformation is shown in FIG. 2.

Table 1 shows a combination of CB sizes constructing control messageconstruction information when the size of a largest control message isn.

TABLE 1 Combinations of the control messages when the size of a largestcontrol message is nCB (n) (n, 1) (n, 2), (n, 2, 1) (n, 3), (n, 3, 1),(n, 3, 2), (n, 3, 2, 1) (n, 4), (n, 4, 1), (n, 4, 2), (n, 4, 2, 1), (n,4, 3), (n, 4, 3, 1), (n, 4, 3, 2), (n, 4, 3, 2, 1) . . . (n, n-1), (n,n-1, 1), . . . (n, n-1, n-2, . . . 1)

The number of types of construction information matched to thecombinations shown in Table 1 is changed according to a value M. FIG. 3is a view showing examples of patterns of control message constructioninformation according to the present invention. For convenience, if itis assumed that M=12 and n=3, patterns shown in FIG. 3 are present ascombinations of (3, 2, 1) (this refers to control message constructioninformation composed of control messages having sizes of 1CB, 2CB and3CB).

The construction information shown in FIG. 3 is configured bycombinations of (3, 2, 1), but the respective numbers of 1CB, 2CB and3CB depend on the value M. For convenience of description, in the abovecombination, a CB having a size next larger than that of a CB having asmallest size is defined as a CB of next lower order and a CB having asize next larger than that of the CB of next lower order is defined as aCB of a next next lower order. If a CB having a size larger than that ofthe CB of the next next lower order is present, the CB is definedaccording to the above-described rule.

For example, if a combination of [3, 2, 1, 1, 1, 1, 1, 1, 1] isconsidered, the numerals refer to the sizes of the CBs, a CB having asmallest size is 1CB, a CB of next lower order is 2CB, which is nextlarger than 1CB, and a CB of next next lower order is 3CB, which is nextlarger than 2CB.

In a method for generating construction information by the same CBcombination, the number of CBs other than the CB having the smallestsize is set to 1, the CB having the smallest size is filled in theremaining area (e.g., [3, 2, 1, 1, 1, 1, 1, 1, 1]), and the number ofCBs of next lower order (e.g., the number of 2CBs) is increased (e.g.,[3, 2, 2, 1, 1, 1, 1, 1], [3, 2, 2, 2, 1, 1, 1], [3, 2, 2, 1]).

Such a process is continuously repeated after the number of CBs of nextnext lower order (e.g., the number of 3CBs) is gradually increased oneby one.

That is, [3, 3, 2, 1, 1, 1, 1] is obtained if the number of CBs of nextnext lower order (e.g., 3CB) is 2, [3, 3, 2, 2, 1, 1] is obtained if thenumber of CBs of next lower order (2CB) is gradually increased, and [3,3, 3, 2, 1] is obtained if the number of CBs of next next lower order is3. If such a process is performed, a specific CB combination may not beobtained according to the value M.

If it is assumed that the value M is 16, a CB combination (3) may not beobtained. If the number of 3CBs is 5, 1CB is necessarily filled in theremaining one, and thus the CB combination (3) cannot be obtained.Instead, the CB combination (3, 1) may be obtained. Accordingly, if thesize of a largest control message among the above-described controlmessages is n, some of the CB combinations constructing the constructioninformation may be excluded according to the value M.

Various patterns constructed by the above-described method according tothe values N and M are used as construction information.

If it is assumed that 5 control messages respectively have sizes of 3CB,1CB, 2CB, 1CB and 3CB, the descending order thereof is [3, 3, 2, 1, 1].The base station aligns the control messages in this order so as totransmit the control messages. At this time, if pattern information of[3, 3, 2, 1, 1, 1, 1] is indicated as construction information, a UEsequentially decodes the control messages in the units of 3CB, 3CB, 2CB,1CB, 1CB, 1CB and 1CB and checks whether control messages thereof arepresent. Since the UE knows in which format the base station transmitsthe control messages, the complexity of decoding according to the sizesof the control messages is decreased. In addition, since a probabilityof a control message having a large size being generated due to amodulation and coding scheme is high, complexity may be decreased byusing the above described method even during demodulation and decoding.

Embodiment 1

If it is assumed that a total of 16CB are allocated for control messagesin a subband generated by dividing a whole band and the sizes of thecontrol messages are allowed up to 1CB to 3CB, 30 pieces of constructioninformation is constructed as shown in Table 2. The base station informsthe UE of index information composed of a total of 5 bits.

TABLE 2 CB Index Pattern combination 1 [1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,1, 1, 1, 1, 1] (1) 2 [2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1](2, 1) 3 [2, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1] (2, 1) 4 [2, 2, 2,1, 1, 1, 1, 1, 1, 1, 1, 1, 1] (2, 1) 5 [2, 2, 2, 2, 1, 1, 1, 1, 1, 1, 1,1] (2, 1) 6 [2, 2, 2, 2, 2, 1, 1, 1, 1, 1, 1] (2, 1) 7 [2, 2, 2, 2, 2,2, 1, 1, 1, 1] (2, 1) 8 [2, 2, 2, 2, 2, 2, 2, 1, 1] (2, 1) 9 [2, 2, 2,2, 2, 2, 2, 2] (2) 10 [3, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1] (3, 1)11 [3, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1] (3, 2, 1) 12 [3, 2, 2, 1, 1,1, 1, 1, 1, 1, 1, 1] (3, 2, 1) 13 [3, 2, 2, 2, 1, 1, 1, 1, 1, 1, 1] (3,2, 1) 14 [3, 2, 2, 2, 2, 1, 1, 1, 1, 1] (3, 2, 1) 15 [3, 2, 2, 2, 2, 2,1, 1, 1] (3, 2, 1) 16 [3, 2, 2, 2, 2, 2, 2, 1] (3, 2, 1) 17 [3, 3, 1, 1,1, 1, 1, 1, 1, 1, 1, 1] (3, 1) 18 [3, 3, 2, 1, 1, 1, 1, 1, 1, 1, 1] (3,2, 1) 19 [3, 3, 2, 2, 1, 1, 1, 1, 1, 1] (3, 2, 1) 20 [3, 3, 2, 2, 2, 1,1, 1, 1] (3, 2, 1) 21 [3, 3, 2, 2, 2, 2, 1, 1] (3, 2, 1) 22 [3, 3, 2, 2,2, 2, 2] (3, 2) 23 [3, 3, 3, 1, 1, 1, 1, 1, 1, 1] (3, 1) 24 [3, 3, 3, 2,1, 1, 1, 1, 1] (3, 2, 1) 25 [3, 3, 3, 2, 2, 1, 1, 1] (3, 2, 1) 26 [3, 3,3, 2, 2, 2, 1] (3, 2, 1) 27 [3, 3, 3, 3, 1, 1, 1, 1] (3, 1) 28 [3, 3, 3,3, 2, 1, 1] (3, 2, 1) 29 [3, 3, 3, 3, 2, 2] (3, 2) 30 [3, 3, 3, 3, 3, 1](3, 1)

In a system, a maximum number of control messages which can betransmitted once may be limited. To this end, a maximum number ofpatterns may be separated from the patterns of Table 1 so as toreconfigure patterns, and the same pattern may be removed so as toreconfigure construction information.

For example, if the maximum number of control messages is limited to 6in Embodiment 1, the patterns and the indexes may be obtained byreconstructing the result of Table 2. Table 3 shows control messageconstruction information, which is obtained by reconstructing the resultof Table 2 if the maximum number of control messages is limited to 6, inthe form of a table. That is, 6 control messages are sequentiallyselected from the left of the patterns of the control messages of Table2 so as to reconstruct patterns and new indexes are applied to thereconstructed patterns.

TABLE 3 If the maximum number of control messages is limited (to 6) CBReconfigured CB New Index Pattern combination pattern combination index1 [1, 1, 1, 1, 1, 1, 1, 1, 1, 1, (1) [1, 1, 1, 1, 1, 1] (1) 1 1, 1, 1,1, 1, 1] 2 [2, 1, 1, 1, 1, 1, 1, 1, 1, 1, (2, 1) [2, 1, 1, 1, 1, 1](2, 1) 2 1, 1, 1, 1, 1] 3 [2, 2, 1, 1, 1, 1, 1, 1, 1, 1, (2, 1) [2, 2,1, 1, 1, 1] (2, 1) 3 1, 1, 1, 1] 4 [2, 2, 2, 1, 1, 1, 1, 1, 1, 1, (2, 1)[2, 2, 2, 1, 1, 1] (2, 1) 4 1, 1, 1] 5 [2, 2, 2, 2, 1, 1, 1, 1, 1, 1,(2, 1) [2, 2, 2, 2, 1, 1] (2, 1) 5 1, 1] 6 [2, 2, 2, 2, 2, 1, 1, 1, 1,1, (2, 1) [2, 2, 2, 2, 2, 1] (2, 1) 6 1] 7 [2, 2, 2, 2, 2, 2, 1, 1, 1,1] (2, 1) [2, 2, 2, 2, 2, 2] (2) 7 8 [2, 2, 2, 2, 2, 2, 2, 1, 1] (2, 1)[2, 2, 2, 2, 2, 2] (2) 9 [2, 2, 2, 2, 2, 2, 2, 2] (2) [2, 2, 2, 2, 2, 2](2) 10 [3, 1, 1, 1, 1, 1, 1, 1, 1, 1, (3, 1) [3, 1, 1, 1, 1, 1] (3, 1) 81, 1, 1, 1] 11 [3, 2, 1, 1, 1, 1, 1, 1, 1, 1, (3, 2, 1) [3, 2, 1, 1, 1,1] (3, 2, 1) 9 1, 1, 1] 12 [3, 2, 2, 1, 1, 1, 1, 1, 1, 1, (3, 2, 1) [3,2, 2, 1, 1, 1] (3, 2, 1) 10 1, 1] 13 [3, 2, 2, 2, 1, 1, 1, 1, 1, 1, (3,2, 1) [3, 2, 2, 2, 1, 1] (3, 2, 1) 11 1] 14 [3, 2, 2, 2, 2, 1, 1, 1, 1,1] (3, 2, 1) [3, 2, 2, 2, 2, 1] (3, 2, 1) 12 15 [3, 2, 2, 2, 2, 2, 1, 1,1] (3, 2, 1) [3, 2, 2, 2, 2, 2] (3, 2) 13 16 [3, 2, 2, 2, 2, 2, 2, 1](3, 2, 1) [3, 2, 2, 2, 2, 2] (3, 2) 17 [3, 3, 1, 1, 1, 1, 1, 1, 1, 1,(3, 1) [3, 3, 1, 1, 1, 1] (3, 1) 14 1, 1] 18 [3, 3, 2, 1, 1, 1, 1, 1, 1,1, (3, 2, 1) [3, 3, 2, 1, 1, 1] (3, 2, 1) 15 1] 19 [3, 3, 2, 2, 1, 1, 1,1, 1, 1] (3, 2, 1) [3, 3, 2, 2, 1, 1] (3, 2, 1) 16 20 [3, 3, 2, 2, 2, 1,1, 1, 1] (3, 2, 1) [3, 3, 2, 2, 2, 1] (3, 2, 1) 17 21 [3, 3, 2, 2, 2, 2,1, 1] (3, 2, 1) [3, 3, 2, 2, 2, 2] (3, 2) 18 22 [3, 3, 2, 2, 2, 2, 2](3, 2) [3, 3, 2, 2, 2, 2] (3, 2) 23 [3, 3, 3, 1, 1, 1, 1, 1, 1, 1](3, 1) [3, 3, 3, 1, 1, 1] (3, 1) 19 24 [3, 3, 3, 2, 1, 1, 1, 1, 1] (3,2, 1) [3, 3, 3, 2, 1, 1] (3, 2, 1) 20 25 [3, 3, 3, 2, 2, 1, 1, 1] (3,2, 1) [3, 3, 3, 2, 2, 1] (3, 2, 1) 21 26 [3, 3, 3, 2, 2, 2, 1] (3, 2, 1)[3, 3, 3, 2, 2, 2] (3, 2) 22 27 [3, 3, 3, 3, 1, 1, 1, 1] (3, 1) [3, 3,3, 3, 1, 1] (3, 1) 23 28 [3, 3, 3, 3, 2, 1, 1] (3, 2, 1) [3, 3, 3, 3, 2,1] (3, 2, 1) 24 29 [3, 3, 3, 3, 2, 2] (3, 2) [3, 3, 3, 3, 2, 2] (3, 2)25 30 [3, 3, 3, 3, 3, 1] (3, 1) [3, 3, 3, 3, 3, 1] (3, 1) 26

As shown in Table 3, since duplicate patterns are present if the maximumnumber of control messages is limited to 6, the total number of indexescan be decreased from 30 to 26.

The patterns shown in Table 3 may be partially combined in order todecrease the effective number of transmission bits. For example, apattern [3, 3, 3, 2, 2, 2, 1] and a pattern [3, 3, 3, 2, 2, 1, 1, 1] maybe replaced with a pattern [3, 3, 3, 2, 2, b, 1]. That is, an underlinedportion of the pattern [3, 3, 3, 2, 2, 2, 1] and an underlined portionof the pattern [3, 3, 3, 2, 2, 1, 1, 1] may be replaced with b so as toindicate [3, 3, 3, 2, 2, b, 1].

FIG. 4 is a view showing an example of control message constructioninformation for decreasing effective number of transmission bits ofcontrol message construction information. As shown in FIG. 4, since bhas a size of 1CB or 2CB, it is troublesome that the UE should decodethis portion with a size of 2CB and 1CB, but the total number of indexesis decreased when an operation for combining the whole pattern usingthis principle is performed.

By expanding this principle, a specific portion of the whole pattern maybe replaced with “b”. For example, the pattern [3, 3, 3, 2, 2, 2, 1] andthe pattern [3, 3, 3, 2, 2, 1, 1, 1] may be replaced with [3, 3, 3, 2,b, 1]. That is, underlined portions of the pattern [3, 3, 3, 2, 2, 2, 1]and the pattern [3, 3, 3, 2, 2, 1, 1, 1] may be replaced with “b” so asto indicate [3, 3, 3, 2, b, 1]. At this time, in order to confirm theportion “b”, decoding should be performed three times with “2, 2”, “2,1, 1” and “1, 1, 1, 1”. Accordingly, the pattern [3, 3, 3, 2, 1, 1, 1,1, 1] may be considered as the same set. The total number of indexes maybe decreased by allowing the system to determine how many CBs areconsidered with respect to the portion denoted by “b” in advance or byallowing the base station to inform the UE of how many CBs areconsidered with respect to the portion denoted by “b.”

In the use of construction information constructed using this principle,a method for informing the UE of the number of control messages beforetransmitting control messages and performing indexing according to thereconstructed construction information may be used.

Although the case where the whole band is divided into a plurality ofsubbands and the control messages are transmitted via allocated subbandsis described up to now, the control messages may be constructed withoutbeing limited according to the subband. That is, even when the band isactually divided into the plurality of subbands for FFR, the controlmessages may be transmitted regardless of the subbands. At this time,power boosting may be considered for high-reliability transmission ofcontrol messages and is suitable for FFR. The principle of generatingthe construction information is equal to the above description exceptthat the size value M of the subband and the number of control messagesare considered with respect to the whole band.

Meanwhile, the following additional messages may be necessary inaddition to the control message construction information.

Information indicating whether or not control messages are present ineach of divided subbands if it is assumed that the whole band is dividedinto K subbands:

For example, this content may be transmitted in a bitmap format. If thewhole band is divided into three subbands, a bitmap composed of 3 bits,such as {b1, b2, b3}, may be used. At this time, the bits b1, b2 and b3sequentially indicate three subbands. Each of the bits of the bitmap hasa value “1” if control messages are present in a subband correspondingthereto and has a value “0” if control messages are not present in asubband corresponding thereto. For example, if control messages arepresent only in a first subband, {b1, b2, b3}={1, 0, 0} is obtained.

Band information:

Total number of control messages

Maximum number (value M) of control messages which can be allowed in thesubband

Maximum number of control messages

Number of control messages in each subband

The present content is applicable to transmission of Unicast ServiceControl Channels (USCCHs) of the IEEE802.16m standard. The USCCH isdivided into User-Specific Control Information (USCI) andNon-User-Specific Control Information (NUSCI). At this time, when USCIis transmitted, the USCI is separately coded. If there is no informationwhen the USCI is transmitted, a UE should perform blind detection. Inthis case, a base station should transmit the above-describedconstruction information using a NUSCI or a Broadcast Channel (BCH). Thebase station aligns the USCI in descending order of the size thereof andtransmits the USCI.

Although the construction information is aligned in descending order inthe present invention, the present invention is applicable to thealignment of the construction information in ascending order.

Hereinafter, a method for constructing control messages according to asecond embodiment of the present invention will be described.

There are various cases where control messages having sizes of 1CB toNCB are present in a band having a size of MCB. However, the basestation aligns the control messages in descending order and transmitsthe control messages. Accordingly, in this case, the number of cases islimited and the pattern thereof is also limited. Accordingly, a methodfor aligning the control messages in descending order and generatinggroups according to the sizes thereof is suggested. For example, afterthe control messages are modulated and/or coded, the control messageshaving a size of 1CB are grouped into Group 1 and the control messageshaving a size of 2CB are grouped into Group 2. Accordingly, the numberof groups is equal to the number of types of the sizes of the controlmessages. The number of all possible groups is considered while settingthe size of the sum of all the control messages to M or less.

Embodiment 2

The following Table 4 shows an example of constructing constructioninformation when it is assumed that the value M of the system is 5 and1CB, 2CB and 4CB allowed as the sizes of the control messages. In Table4, Group 1 is a group of control messages having a size of 1CB, Group 2is a group of control messages having a size of 2CB, and Group 3 is agroup of control messages having a size of 4CB.

TABLE 4 Index Group 1 (1CB) Group 2 (2CB) Group 3 (4CB) 0 0 0 0 1 1 0 02 2 0 0 3 3 0 0 4 4 0 0 5 5 0 0 6 0 1 0 7 1 1 0 8 2 1 0 9 3 1 0 10 0 2 011 1 2 0 12 0 0 1 13 1 0 1

As can be seen from Table 4, the total size of all the control messageshaving a certain index is equal to or less than M (5 in the presentembodiment). As in the above example, Group 1 to Group 3 may besequentially connected such that the values thereof are aligned indescending or ascending order. The other methods, e.g., a method forperforming alignment in order of total sizes of all the control messages(ascending order or descending order) and the like may be considered.

Embodiment 3

The following Table 5 shows the construction of a control messagealignment pattern aligned according to the total sizes of all thecontrol messages using Table 4. In Table 5, Group 1 is a group ofcontrol messages having a size of 1CB, Group 2 is a group of controlmessages having a size of 2CB, and Group 3 is a group of controlmessages having a size of 4CB. In addition, in Table 5, Group 1 to Group3 are denoted by G1, G2 and G3, respectively. Value in the parenthesesin each of the groups denote the number of control messages belonging tothe group.

TABLE 5 Total size of control messages [Unit: CB] Index 2 1 2 3 4 5 1G1(1), G2(0), G1(2), G2(0), G1(3), G1(4), G1(5), G3(0) G3(0) G2(0),G3(0) G2(0), G3(0) G2(0), G3(0) 2 — G1(0), G2(1), G1(1), G2(1), G1(2),G2(1), G1(3), G2(1), G3(0) G3(0) G3(0) G3(0) 3 — — — G1(0), G2(2),G1(1), G2(2), G3(0) G3(0) 4 — — — G1(0), G2(0), G1(1), G3(1) G2(0),G3(1)

All 13 types (Indexes 1 to 13) of Embodiment 1 are shown in Table 5.Accordingly, the indexes indicating the control message construction canbe sequentially generated by referring to the total size of the controlmessages and the value of Index 2 of Table 5.

Embodiment 4

According to another embodiment of the present invention, in order todecrease the effective number of bits of the transmitted index, allpossible combinations of each group excluding a specific group n may beconsidered while the total size of all the control messages is fixed toM. The control message corresponding to the excluded Group n may beincluded in blind decoding. For example, if n=1 and M=5, the UE mayperform blind decoding with respect to the control message included inGroup 1 (group having a size of 1CB). The following Table 6 shows theconstruction of a control message alignment pattern excluding Group 1.

TABLE 6 Index Group 1 (1CB) Group 2 (2CB) Group 3 (4CB) 0 0-5 0 0 1 0-31 0 2 0 or 1 2 0 3 0 or 1 0 1

That is, in Table 6, if an index is 1, the number of control messageshaving a size of 2CB is 1, the number of control messages having a sizeof 4CB is 0, and the number of control messages having a size of 1CB isany one of 0 to 3. If it is assumed that a base station aligns controlmessages in order of size and transmits the control messages, Group 3and Group 2 are decoded first and the remaining control messages areblind-decoded in the unit of 1CB up to the total size (M) of the controlmessages.

Meanwhile, in order to reduce complexity of blind decoding in the unitof 1CB, a base station may further transmit the following informationtogether with an index.

The number of control messages included in Group 1 or total size ofGroup 1

The total number of control messages included in each of the groups andthe total size (e.g., CB or Resource Unit (RU) size) of bands (Group 1to 3) occupied by actual control messages

In the use of construction information constructed by such a principle,a method for first informing the UE of the number of control messages orthe size of the resource used (e.g., the number of CBs or the number ofRUs) before transmitting the control messages and then performingindexing may save the UE efforts for performing additional blinddetection, by informing the UE of the total number of control messageswhich are currently constructed or the size thereof in advance.

Meanwhile, the total number of control messages or the size thereof maybe changed according to the situation of the system. For example, thevalue M may be changed according to the bandwidth of the system or theincrease in the number of control messages to be transmitted to the UEin the system. Since the above-described methods consider the totalnumber of cases when the value M is changed, the number of all casesconsidering M₁ is a subset of the number of all cases considering M₂with respect to different values of M (M₁<M₂). Accordingly, a method forpreparing a table with respect to a largest value M allowed by thesystem and reconstructing and using indexes according to the change ofthe value M may be considered.

For example, although, in Embodiment 2, if M=5 and construction isperformed as shown in Table 4 such that all the values (total size ofcontrol messages is 1CB to 5CB) of the table are used, indexes may bereconstructed in consideration of the total size of control messages of1CB to 4CB when the value M is changed to 4.

Meanwhile, a specific group may be subjected to blind decoding in orderto reduce the effective number of bits of the index. The following Table7 is obtained if a group having n=1, that is, Group 1 (group having asize of 1CB), is subjected to blind decoding as in Embodiment 3.

TABLE 7 M [Unit: CB] Index 2 1 2 3 4 5 0 G1(0-1), G1(0-2), G1(0-3),G1(0-4), G1(0-5), G2(0), G2(0), G2(0), G2(0), G3(0) G2(0), G3(0) G3(0)G3(0) G3(0) 1 — G1(0), G1(0-1), G1(0-2), G1(0-3), G2(1), G2(1), G2(1),G2(1), G3(0) G3(0) G3(0) G3(0) 2 — — — G1(0), G2(2), G1(0-1), G3(0)G2(2), G3(0) 3 — — — G1(0), G2(0), G1(0-1), G3(1) G2(0), G3(1)

If the value M requested by the system is transmitted to all UEs (e.g.,using a BCH), Index 2 which is the control message constructioncorresponding to the value M is used.

As another method using Table 6, if the total number of control messagesconstructed in a current frame is N (0≦N≦M), a band correspondingthereto is found in Table 6 using the value N instead of the value M andconstruction information is informed using Index 2 correspondingthereto. The following Table 8 shows construction informationconstructed when the total number of control messages constructed in thecurrent frame is N.

TABLE 8 N [Unit: CB] Index 2 1 2 3 4 5 0 G1(1-1), G1(1-2), G1(1-3),G1(1-4), G1(1-5), G2(0), G3 G2(0), G3 G2(0), G2(0), G3(0) G2(0), (0) (0)G3(0) G3(0) 1 — G1(0), G1(0-1), G1(0-2), G1(0-3), G2(1), G2(1), G2(1),G2(1), G3(0) G3(0) G3(0) G3(0) 2 — — — G1(0), G2(2), G1(0-1), G3(0)G2(2), G3(0) 3 — — — G1(0), G2(0), G1(0-1), G3(1) G2(0), G3(1)

That is, if the value N is 5 and Index 2 is 1, construction informationis G1(0-3), G2(1), G3(0), and, if the value N is 3 and Index 2 is 1,construction information is G1(0-1), G2(1) and G3(0). At this time, 2bits are necessary for indicating Index 2 when the value N is 5, butonly 1 bit is necessary for indicating Index 2 when the value N is 3.That is, since the effective number of bits for indicating Index 2 isautomatically determined using Table 8 by setting the value M, thenumber of bits necessary for indicating construction information isdecreased.

Table 7 may be generated from Table 5.

Since Group 1 is subjected to blind decoding, the band of Group 1 inTable 5 is changed and applied. Accordingly, the same table may be usedwhen the system performs transmission in consideration of the number ofall cases as in Embodiment 2 and when a specific group is subjected toblind decoding as in Embodiment 3.

When the number of all possible cases is considered and when some groupsare subjected to blind decoding, the system may inform all the UEs ofthe features of this construction information using a BCH orNon-User-Specific Control Information (NUSCI). In this case, theconstruction shown in Table 4 or Table 6 may be efficiently used.

In all the above-described methods, if there is no control message, anindex corresponding thereto may be omitted. For example, in Embodiments1 to 3, when the number of control messages is 0 in Group 1 to 3, anindex corresponding thereto is not necessary if the total number ofcontrol messages included in each group is known.

The present invention is applicable to transmission of USCCHs of theIEEE802.16m standard. The USCCH is divided into USCI and NUSCI. At thistime, when USCIs are transmitted, the USCI is separately coded. If thereis no information when the USCI is transmitted, a UE should performblind detection. In this case, a base station should transmit theabove-described construction information using a NUSCI or a BCH. Thebase station aligns the USCI in descending order of the size andtransmits the USCI.

Although the construction information described in the present inventionis aligned in descending order, the present invention is applicable tothe construction information aligned in ascending order.

Embodiment 5

The value M may be actually changed according to the construction of thesystem. The following Table 9 shows indexes according to various valuesM which may be constructed in the system. G1, G2, G3, G4 and G5 denotethe cases where the sizes of the control messages are respectively 1CB,2CB, 4CB, 8CB and 16CB. Group 1 may be omitted because a UE performsblind detection from a point of time, when Group 2 is completed, to MCB.

TABLE 9 M [Unit: CB] Index 2 1 2 3 4 5 0 G1(0-1), G1(0-2), G1(0-3),G1(0-4), G1(0-5), G2(0), G2(0), G2(0), G2(0), G2(0), G3(0), G3(0),G4(0), G3(0), G3(0), G3(0), G4(0), G5(0) G5(0) G4(0), G4(0), G4(0),G5(0) G5(0) G5(0) 1 — G1(0), G1(0-1), G1(0-2), G1(0-3), G2(1), G2(1),G2(1), G2(1), G3(0), G3(0), G4(0), G3(0), G3(0), G4(0), G5(0) G5(0)G4(0), G4(0), G5(0) G5(0) 2 — — — G1(0), G2(2), G1(0-1), G2(2), G3(0),G4(0), G3(0), G4(0), G5(0) G5(0) 3 — — — G1(0), G2(0), G1(0-1), G2(0),G3(1), G4(0), G3(1), G4(0), G5(0) G5(0) M [Unit: CB] Index 2 6 7 8 9 100 G1(0-6), G1(0-7), G1(0-8), G1(0-9), G1(0-10), G2(0), G3 G2(0), G3G2(0), G3 G2(0), G3 G2(0), G3 (0), G4(0), G5 (0), G4(0), G5 (0), G4(0),G5 (0), G4(0), G5 (0), G4(0), G5 (0) (0) (0) (0) (0) 1 G1(0-4), G1(0-5),G1(0-6), G1(0-7), G1(0-8), G2(1), G3 G2(1), G3 G2(1), G3 G2(1), G3G2(1), G3 (0), G4(0), G5 (0), G4(0), G5 (0), G4(0), G5 (0), G4(0), G5(0), G4(0), G5 (0) (0) (0) (0) (0) 2 G1(0-2), G1(0-3), G1(0-4), G1(0-5),G1(0-6), G2(2), G3 G2(2), G3 G2(2), G3 G2(2), G3 G2(2), G3 (0), G4(0),G5 (0), G4(0), G5 (0), G4(0), G5 (0), G4(0), G5 (0), G4(0), G5 (0) (0)(0) (0) (0) 3 G1(0), G2(3), G1(0-1), G1(0-2), G1(0-3), G1(0-4), G3(0),G4(0), G2(3), G3 G2(3), G3 G2(3), G3 G2(3), G3 G5(0) (0), G4(0), G5 (0),G4(0), G5 (0), G4(0), G5 (0), G4(0), G5 (0) (0) (0) (0) 4 G1(0-2),G1(0-3), G1(0), G2(4), G1(0-1), G1(0-2), G2(0), G3 G2(0), G3 G3(0),G4(0), G2(4), G3 G2(4), G3 (1), G4(0), G5 (1), G4(0), G5 G5(0) (0),G4(0), G5 (0), G4(0), G5 (0) (0) (0) (0) 5 G1(0), G2(1), G1(0-1),G1(0-4), G1(0-5), G1(0), G2(5), G3(1), G4(0), G2(1), G3 G2(0), G3 G2(0),G3 G3(0), G4(0), G5(0) (1), G4(0), G5 (1), G4(0), G5 (1), G4(0), G5G5(0) (0) (0) (0) 6 G1(0-2), G1(0-3), G1(0-6), G2(1), G3 G2(1), G3G2(0), G3 (1), G4(0), G5 (1), G4(0), G5 (1), G4(0), G5 (0) (0) (0) 7G1(0), G2(2), G1(0-1), G1(0-4), G3(1), G4(0), G2(2), G3 G2(1), G3 G5(0)(1), G4(0), G5 (1), G4(0), G5 (0) (0) 8 G1(0), G2(0), G1(0-1), G1(0-2),G3(2), G4(0), G2(0), G3 G2(2), G3 G5(0) (2), G4(0), G5 (1), G4(0), G5(0) (0) 9 G1(0), G2(0), G1(0-1), G1(0), G2(3), G3(0), G4(1), G2(0), G3G3(1), G4(0), G5(0) (0), G4(1), G5 G5(0) (0) 10 G1(0-2), G2(0), G3 (2),G4(0), G5 (0) 11 G1(0), G2(1), G3(2), G4(0), G5(0) 12 G1(0-2), G2(0), G3(0), G4(1), G5 (0) 13 G1(0), G2(1), G3(0), G4(1), G5(0)

In Table 9, at an index 0, Group 1 is denoted by G1(0-M). If the numberof control messages which are currently transmitted (or the total sizeof control messages) is separately transmitted, G1(0-M) of Group 1indicated at an index 0 may be represented by G1(1-M). This is because,if the number of control messages (or the total size of controlmessages) is 0, there is no control message to be transmitted. As theconstruction table, that obtained by switching Table 7 to Table 8 inEmbodiment 4 may be used without modification. That is, indexes may begenerated based on the total number of control messages, which arecurrently constructed, in consideration of the value N, instead of thevalue M.

Examples of the method for setting the groups include the followingvarious methods in addition to the method using the size.

A downlink control message is actually modulated and coded so as to betransmitted. At this time, in order to apply a Modulation and CodingScheme (MCS), the downlink control message may be segmented into aplurality of subblocks. For convenience, the downlink control message iscalled a downlink control message Information Element (IE), a segmentedsubblock is called an extended IE, and a control signal which isactually transmitted after applying the MCS is called an allocated IE.In addition, the basic size unit of the allocated IE is called a MinimumA-MAP Logical Resource Unit (MLRU). Control messages are transmitted ina state of being grouped according to a specific purpose, and suitableinformation about grouping is transmitted. For example, the examples ofthe downlink control message IE may include a downlink/uplink (DL/UL)basic assignment IE, a UL basic assignment IE, a DL/UL group resourceallocation IE, and a DL/UL persistent IE.

The following cases may be considered as the example of the groupingmethod.

In a first case, grouping is performed such that control messages aredivided into control messages for allowing a UL ACK/NACK channel indexto be implicitly used and otherwise. For example, control messages maybe grouped into a group 1 composed of DL basic assignment IEs and agroup 2 composed of the other types of IEs.

In a second case, grouping is performed such that control messages aredivided into control messages of a user who may implicitly use a ULACK/NACK channel index and otherwise. For example, control messages maybe grouped into a group 1 composed of DL/UL basic assignment IEs and agroup 2 composed of the other types of IEs. At this time, the controlmessage IEs of one user may be successively transmitted.

In the first and second cases, the examples of the method of implicitlyusing the ACK/NACK channel index include a method of using the order ofcontrol messages as the ACK/NACK channel index. That is, if suchgrouping method is used, supplementary signaling for the ACK/NACKchannel index is not necessary.

In a third case, grouping is performed according to the sizes of controlmessage IEs. For example, the control messages may be grouped into agroup 1 composed of control messages having a size of 56 bits and agroup 2 composed of control messages having a size of 90 bits.

In a fourth case, grouping is performed according to an extended IE anda non-extended IE. That is, control messages may be grouped into a group1 composed of extended IEs and a group 2 composed of the other types ofIEs (e.g., basic IEs). The extended IEs refer to subblocks generated bysegmenting an original control message into a plurality of portions ifthe amount of information of the original control message exceeds thelength of the basic control message allowed by the system as describedabove. At this time, the extended IEs segmented into the plurality ofsubblocks may be successively transmitted.

In a fifth case, grouping is performed according to MCS levels. Forexample, control messages may be grouped into a group 1 composed ofcontrol messages having an MCS level of Qaudrature Phase Shift Keying(QPSK) ½ and a group 2 composed of control messages having an MCS levelof QPSK ⅛.

In a sixth case, grouping is performed according to the sizes of theallocated IEs. For example, control messages may be grouped into a group1 composed of 2MLRUs and a group 2 composed of 4MLRUs. The allocated IEsrefer to those allocated to actual resource areas after applying the MCSto the control messages as described above.

In a seventh case, a combination of the grouping methods of the firstcase to the sixth case is used.

For example, after control messages are grouped according to the thirdcase, the fifth case may be applied to the groups generated by thegrouping. For example, control messages may be grouped into a group 1composed of control messages having a size of 56 bits and an MCS levelof QPSK ½, a group 2 composed of control messages having a size of 56bits and an MCS level of QPSK ⅛, a group 3 composed of control messageshaving a size of 90 bits and an MCS level of QPSK ½, and a group 4composed of control messages having a size of 90 bits and an MCS levelof QPSK ⅛.

The number of groups may be changed according to circumference and themethod may be changed according to the purpose thereof.

Embodiment 6

The grouping method may be performed according to the MCS levels insteadof sizes. That is, blind detection may be performed by performinggrouping according to the MCS levels of the control messages andinforming the UE of the number of control messages in each group.

For example, if control messages are modulated/demodulated and codedusing QPSK 1/16 (MCS4), QPSK ⅛ (MCS3), QPSK ¼ (MCS2) and QPSK ½ (MCS1),indexes are generated and transmitted by the above-described methodusing construction information indicating how many control messages arepresent in each MCS level.

Meanwhile, in the case where a base station transmits constructioninformation according to the sizes thereof, blind detection can beeasily performed by aligning construction information according to theMCS levels in each of the groups divided according to sizes (aligningconstruction information in order of from MCS1 to MCS4 or from MCS4 toMCS1) and transmitting the construction information. In contrast, in thecase where groups are constructed according to MCS levels, blinddetection can be easily performed by aligning construction information(in descending order or ascending order) according to the sizes thereofin each group and transmitting the construction information.

Meanwhile, in the transmission of each group, the number of controlmessages in each actual group may be directly signaled.

An example of the above-described control messages, an Advanced-MAP(A-MAP) Information Element (IE) of an IEEE802.16m system may beconsidered. If grouping is performed according to the sizes of A-MAPresource allocation units (hereinafter, referred to as A-MAP IEallocation units) allocated to actual A-MAP channels after applyingmodulation/demodulation coding to A-MAP IEs, the sizes of the A-MAP IEallocation units present in each group may be set to be equal. FIG. 5 isa view showing a control message alignment pattern according to anembodiment of the present invention. As shown in FIG. 5, after applyingmodulation/demodulation coding, the A-MAP IE allocation units arealigned according to the sizes thereof and the A-MAP IE allocation unitshaving the same size to configure a group.

After applying modulation/demodulation coding to A-MAP IEs, the A-MAP IEallocation units allocated to actual A-MAP channels may be alignedaccording to the sizes thereof, and the A-MAP IE allocation units may bealigned according to the MCS levels thereof within the A-MAP IEallocation units having the same size.

FIG. 6 is a view showing a control message alignment pattern accordingto an embodiment of the present invention. As shown in FIG. 6, A-MAP IEallocation units having the same MCS level and the same size may begrouped. If A-MAP IEs having a size of 1MLRU and 2MLRU are present andmodulation/demodulation coding such as QPSK ½ and QPSK ¼ (the types ofthe MCS may be differently applied) is performed with respect to theA-MAP IEs, the sizes of the A-MAP IE allocation units allocated to theactual A-MAP channels are 1MLRU, 2MLRU and 4MLRU. The MLRU is the unitsize of the A-MAP IE. At this time, those obtained by performingmodulation/demodulation coding with respect to A-MAP IEs having 1MLRUusing QPSK ½ are present as the A-MAP IE allocation unit having a sizeof 1MLRU, those obtained by performing modulation/demodulation codingwith respect to A-MAP IEs having 2MLRU using QPSK ½ and those obtainedby performing modulation/demodulation coding with respect to A-MAP IEshaving 1MLRU using QPSK ¼ are present as the A-MAP IE allocation unithaving a size of 2MLRU, and those obtained by performingmodulation/demodulation coding with respect to A-MAP IEs having 2MLRUusing QPSK ¼ are present as the A-MAP IE allocation units having a sizeof 4MLRU. Accordingly, a total of 4 groups are present, and indexinformation defined by the size of each group (or the number of A-MAP IEallocation units) or a specific pattern may be transmitted in order toeasily perform blind detection. The above information may be transmittedvia a non-user-specific A-MAP.

Meanwhile, if the A-MAP IE allocation units are grouped according to theMCS levels thereof, the sizes of the A-MAP IE allocation units presentin the groups may be different, but the MCS levels of the A-MAP IEallocation units present in the groups may be set to be equal. FIG. 7 isa view showing a control message alignment pattern according to anembodiment of the present invention. In FIG. 7, A-MAP IE allocationunits are grouped according to the MCS levels thereof after applyingmodulation/demodulation coding to A-MAP IEs.

After applying modulation/demodulation coding to A-MAP IEs, the A-MAP IEallocation units allocated to the actual A-MAP channels may be alignedaccording to MCS levels and may be realigned according to the sizesthereof within the A-MAP IE allocation units having the same MCS levels.FIG. 8 is a view showing a control message alignment pattern accordingto an embodiment of the present invention. As shown in FIG. 8, A-MAP IEallocation units having the same MCS level and the same size may begrouped. If it is assumed that A-MAP IEs having a size of 1MLRU and2MULRU are present and modulation/demodulation is performed with respectto the A-MAP IEs using QPSK ½ and QPSK ¼ (the type of the MCS may bedifferently applied), the sizes of the A-MAP IE allocation unitsallocated to the actual A-MAP channels are 1MLRU, 2MLRU and 4MLRU. Atthis time, those obtained by performing modulation/demodulation codingwith respect to A-MAP IEs having 1MLRU using QPSK ½ are present as theA-MAP IE allocation unit having a size of 1MLRU, those obtained byperforming modulation/demodulation coding with respect to A-MAP IEshaving 2MLRU using QPSK ½ and those obtained by performingmodulation/demodulation coding with respect to A-MAP IEs having 1MLRUusing QPSK ¼ are present as the A-MAP IE allocation unit having a sizeof 2MLRU, and those obtained by performing modulation/demodulationcoding with respect to A-MAP IEs having 2MLRU are present as the A-MAPIE allocation unit having a size of 4MLRU. Accordingly, a total of 4groups are present, and index information defined by the size of eachgroup (or the number of A-MAP IE allocation units) or a specific patternis transmitted in order to easily perform blind detection. The aboveinformation may be transmitted via a non-user-specific A-MAP.

A method for broadcasting such information to all UEs within a cell maybe considered as a method for informing the UE of such information.

In the IEEE802.16m system, the above information may be transmittedusing a non-user-specific A-MAP or a Superframe Header (SFH).

At this time, in the non-user specific A-MAP, if multiple frequencypartitioning such as FFR is applied, the case where a non-user-specificA-MAP is present in each partition, the case where A-MAP constructioninformation of a certain partition is indicated by a non-user-specificA-MAP allocated to another partition, and the case where anon-user-specific A-MAP is present in a reuse partition one by one maybe considered. When the non-user-specific A-MAP is present in eachpartition, the A-MAP construction information of the partition suggestedby the present invention is transmitted by the partition.

In the case where a non-user-specific A-MAP is not present in allpartitions, the A-MAP construction information of a certain partitionmay be indicated by a non-user-specific A-MAP allocated to anotherpartition. For example, if a reuse 1 partition and a reuse 3 partitionare simultaneously applied, the transmission of the non-user-specificA-MAP only by the power boosting reuse-N partition or reuse 1 partitionmay be considered. At this time, a method for transmitting A-MAPconstruction information (index information using the above-describedindex generating method, the size of each group or the number of A-MAPIE allocation units) of each partition to the non-user-specific A-MAPmay be applied. In addition, if the non-user-specific A-MAP istransmitted by the power boosting specific reuse-N partition and reuse 1partition, A-MAP information corresponding to the partition may beindicated by the non-user-specific A-MAP of the partition.

A group may be defined by the total size of A-MAP IE allocation units ofeach partition. That is, if a total of four partitions are configured byapplying multiple partitioning, four groups are present, and a UE may beinformed of index information using the above-described index generatingmethod or the size of each group according to partitions (or the numberof A-MAP IE allocation units) using a non-user-specific A-MAP or a SFH.

The A-MAP construction information of the partition suggested by thepresent invention when a non-user-specific A-MAP is present in eachpartition is transmitted by the partition.

Hereinafter, the construction of a non-user-specific A-MAP and a methodfor transmitting the construction information when multiple FrequencyPartitions (FPs) such as FFR are applied in a system will be described.

The number of FPs which may be considered for the same reason of FFR maybe determined according to an operation method. For example, if FFR ⅓(that is, a frequency reuse rate related to FFR is ⅓) is applied as anFFR scheme, the number of FPs is three and, if FFR ⅓ and FFR 1 areapplied, the number of FPs is four.

In consideration of the characteristics (e.g., power boosting) of theFPs, a specific MCS level may be limited and used according to FPs. Forexample, QPSK ½ is applied to a power boosting FP, QPSK ½ and/or QPSK ⅛is applied to an FFR 1 partition, and QPSK ⅛ is applied to apowered-down FP.

Meanwhile, control messages may be present in all FPs or only in apredetermined FP. If control messages are present only in thepredetermined FP, for example, in FFR ⅓, control messages may be presentonly in a power boosting FP, and, in FFR ⅓ and FFR 1, control messagesmay be present only in a power boosting FP and/or an FP of FFR 1.

In addition, if control messages are grouped and transmitted, thegrouping method suggested by the present invention may be applied to anFP in which the control messages are present.

Hereinafter, examples of grouping and transmitting control messages in asystem to which FFR is applied will be described.

In a first example, it is assumed that there are A type and B type inthe size of an Assignment (A)-A-MAP IE, the number of FPs is 1 (FFR 1 isapplied), and QPSK ½ and QPSK ⅛ are applied as available MCSs. QPSK ½and QPSK ⅛ are applied to the A type such that a 1MLRU allocation unitand a 4MLRU allocation unit are generated and QPSK ½ and QPSK ⅛ areapplied to the B type such that a 2MLRU allocation unit and an 8MLRUallocation unit are generated. Accordingly, after applying the MCS,1MLRU, 2MLRU, 4MLRU and 8MLRU are present as the A-MAP IE allocationunit. The generated 1MLRU may be set to a group 1, the 2MLRU may be setto a group 2, the 4MLRU may be set to a group 3, and the 8MLRU may beset to a group 4. At this time, the maximum number of A-A-MAP IEs whichcan be transmitted may be determined according to the size of theresource area allocated for A-A-MAP. FIG. 9 is a view showing a controlmessage alignment pattern if FFR is applied, according to an embodimentof the present invention. As shown in FIG. 9, the generated MLRUs maymap resources having the same IE size and the same MCS level to groupscomposed of logically consecutive MLRUs.

In a second example, it is assumed that there are A type and B type inthe size of an A-A-MAP IE, and the number of FPs is 3 (FFR ⅓ isapplied). In addition, the A-A-MAP is present only in a power boostingpartition and the used MCS is limited to QPSK ½. Since the QPSK ½ isapplied to the A type and the B type such that a 1MLRU allocation unitand a 2MLRU allocation unit are generated, after applying the MCS, 1MLRUand 2MLRU are present as the A-A-MAP IE allocation unit. The generated1MLRU is set to a group 1 and the 2MLRU is set to a group 2. FIG. 10 isa view showing a control message alignment pattern if FFR is applied,according to an embodiment of the present invention. As shown in FIG.10, it is possible to map resources having the same IE size and the sameMCS level to groups composed of logically consecutive MLRUs.

In a third example, it is assumed that there are A type and B type inthe size of an A-A-MAP IE, and the number of FPs is 4 (FFR ⅓ and FFR 1are applied). In consideration of the characteristics (e.g., powerboosting) of the FPs, a specific MCS level is limited and used accordingto FPs. For example, QPSK ½ is applied to an FFR ⅓ power boostingpartition, and QPSK ⅛ is applied to an FFR 1 partition, as an availableMCS. QPSK ½ is applied to the A type and the B type in the FFR ⅓ powerboosting partition such that a 1MLRU allocation unit and a 2MLRUallocation unit are generated, and QPSK ⅛ is applied to the A type andthe B type in an FFR 1 partition such that a 4MLRU allocation unit andan 8MLRU allocation unit are generated. Accordingly, in this case, afterapplying the MCS, 1MLRU, 2MLRU, 4MLRU and 8MLRU are present as theA-A-MAP IE allocation unit. The generated 1MLRU may be set to a group 1,the 2MLRU may be set to a group 2, the 4MLRU may be set to a group 3,and the 8MLRU may be set to a group 4. FIG. 11 is a view showing acontrol message alignment pattern if FFR is applied, according to anembodiment of the present invention. As shown in FIG. 10, it is possibleto map resources having the same IE size and the same MCS level togroups composed of logically consecutive MLRUs.

In a fourth example, it is assumed that there are A type and B type inthe size of an A-A-MAP IE, and the number of FPs is 4 (FFR ⅓ and FFR 1are applied). In consideration of the characteristics (e.g., powerboosting) of the FPs, a specific MCS level is limited and used accordingto FPs. For example, QPSK ½ is applied to an FFR ⅓ power boostingpartition, and QPSK ½ and QPSK ⅛ are applied to an FFR 1 partition as anavailable MCS. QPSK ½ is applied to the A type and the B type in the FFR⅓ power boosting partition such that a 1MLRU allocation unit and a 2MLRUallocation unit are generated, QPSK ½ is applied to the A type and the Btype in an FFR 1 partition such that a 1MLRU allocation unit and a 2MLRUallocation unit are generated, and QPSK ⅛ is applied to the A type andthe B type such that a 4MLRU allocation unit and an 8MLRU allocationunit are generated.

In this case, after applying the MCS, 1MLRU, 2MLRU, 4MLRU and 8MLRU arepresent as the A-MAP IE allocation unit. The 1MLRU allocation unit ofthe FFR ⅓ power boosting partition may be set to a group 1, the 2MLRUmay be set to a group 2, the 1MLRU allocation unit of the FFR 1partition may be set to a group 3, the 2MLRU may be set to a group 4,the 4MLRU may be set to a group 5, and the 8MLRU may be set to a group6. FIG. 12 is a view showing a control message alignment pattern if FFRis applied, according to an embodiment of the present invention. Asshown in FIG. 12, the generated MLRUs may map resources having the sameIE size and the same MCS level to groups composed of logicallyconsecutive MLRUs. At this time, if the resources have the same MCSlevel and the same IE size but are present in different FPs, resourcesmay be mapped to different groups.

In a fifth example, it is assumed that there are A type and B type inthe size of an A-A-MAP IE, and the number of FPs is 4 (FFR ⅓ and FFR 1are applied). The same MCS level is limited and used in all the FPs anda power level may be adjusted as necessary in order to maintain linkperformance. For example, QPSK ½ may be used as an available MCS. QPSK ½is applied to the A type and the B type in the FFR ⅓ power boostingpartition such that a 1MLRU allocation unit and a 2MLRU allocation unitare generated, and QPSK ½ is applied to the A type and the B type in theFFR 1 partition such that a 1MLRU allocation unit and a 2MLRU allocationunit are generated.

At this time, if the A-A-MAPS have the same MCS level and the same IEsize but are present in different FPs, the A-A-MAPs may be grouped todifferent groups. Accordingly, the 1MLRU allocation unit of the FFR ⅓power boosting partition may be set to a group 1, the 2MLRU may be setto a group 2, the 1MLRU allocation unit of the FFR 1 partition may beset to a group 3, and the 2MLRU may be set to a group 4. FIG. 13 is aview showing a control message alignment pattern if FFR is applied,according to an embodiment of the present invention. As shown in FIG.13, the generated MLRUs may map resources having the same IE size andthe same MCS level to groups composed of logically consecutive MLRUs. Atthis time, if the resources have the same MCS level and the same IE sizebut are present in different FPs, resources may be mapped to differentgroups.

That is, if a plurality of FPs is present due to the FFR as describedabove, as the example of the grouping method, any one of theabove-described grouping methods may be applied within the FP in whichcontrol messages are present, and a combination of the above-describedgrouping methods may be used.

Hereinafter, a method for signaling a method for transmitting an A-A-MAPIE via control channels for performing broadcast to a plurality of UEswill be described. If various FPs are allowed in the system, there is aneed for efficiently signaling the FPs. For example, the numbers of theA-A-MAP IE allocation units of each group and the size of each group maybe signaled. Alternatively, the number of all possible A-A-MAP IEallocation units of each group may be generated in a table and an indexsuitable for the transmission method may be signaled. At this time,tables may be generated with respect to the maximum number of MLRUs(e.g., the maximum number of MLRUs is 16, 17, 18, 19, 20, 21, 23, 33,34, 35, 36, 37, 38, 39, 40, 41, 42) and an index may be selected from atable suitable for the transmission method so as to be transmitted.

Hereinafter, a method for generating a table and signaling an index willbe described.

In a first case, a common superset table which is independent of FPconstruction may be generated and the indexes of the table may be used.For example, even when the number of FPs is 1, 3 or 4, a table to whichall the FPs are applicable may be generated. To this end, a supersettable including all groups which may be generated when the number of FPsis 1, 3, 4 may be generated. At this time, a superset is determinedaccording to a transmission method. For example, in order to include allthe above-described first, second and third examples, a superset tableto which a total of four groups are applicable is generated. Inaddition, in order to include all the above-described first, second andfifth examples, a superset table to which a total of four groups areapplicable is generated. In order to include all the above-describedfirst, second and fourth examples, a superset table to which a total ofsix groups are applicable is generated.

In a second case, a superset table may be generated and indexes relatedto a specific FP may be signaled as a subset of the superset table. Forexample, if a superset table, to which a total of four groups areapplicable, is present in order to include all the first, second andthird examples, the superset table may be used for the first and thirdexamples, and, in the second example, indexes are selectively extractedfrom the superset table so as to be signaled.

In a third case, tables may be separately generated and used accordingto FP construction. That is, different tables may be applied accordingto FPs. For example, in a system in which the number of FPs is 1, 3 or4, an optimal table suitable for each case is generated and indexes ofthe table are signaled. At this time, the table generation principle isequal to the above-described method. In the first example, indexes of atable generated using the number of units of each of four groups or agroup size may be signaled. In addition, in the second example, indexesof a table generated using the number of units of each of two groups ora group size may be signaled. In addition, in the third to fifthexamples, indexes of a table generated using the number of groups or agroup size may be signaled.

The number of FPs or the types of tables which should be used may bebroadcasted to UEs using a BCH or signaled using a non-user-specificcontrol message within an A-MAP before using indexes.

In a fourth case, a table may be generated by combining groups havingthe same properties (e.g., the same MCS level and/or IE size) amonggroups which are present in FPs. For example, in the fourth example orthe fifth example, a group 3 and a group 1 have the same properties anda group 4 and a group 2 have the same properties. In this case, thegroup 1 and the group 3 are combined to form a group A and the group 2and the group 4 are combined to form a group B, thereby generating atable. In this case, a UE may increase the complexity of blind detectionbefore combining the table in the FPs for decoding the control messages.

Meanwhile, in addition to the criterion for grouping the controlmessages described up to now, the control messages may be groupedaccording to the uses of the control messages, e.g., uplink allocation,downlink allocation, or downlink persistent allocation.

Although the grouping criterion is the MCS levels or the sizes of thecontrol messages in the above description, the grouping criterion is notlimited to the above examples, and grouping may be performed based onvarious criteria and the above description is applicable to the variouscriteria. The method for generating the table supporting various FPs andsignaling method may be used in combination with a method for generatinga table supporting various bands and a control signaling period. As themethod for generating the table, a method for generating a table inconsideration of all possible combinations of groups or a method forreducing signaling overhead may be applied.

A user equipment can receives information about a control messagealignment pattern in advance before receiving control messages by usingabove described method. Then, the user equipment can receive the controlmessages. The user equipment can detect its control message from thereceived control messages by using control message alignment patternincluded in the information.

Thus, it is possible to easily perform blind detection while minimizingoverhead, by informing a user of information about a control messagealignment pattern in advance before transmitting control messages.Accordingly, it is possible to reduce complexity and time for confirmingthe control messages.

FIG. 14 is a block diagram showing the construction of a device which isapplicable to a base station and a UE and is able to perform theabove-described methods. As shown in FIG. 14, the device 60 includes aprocessing unit 61, a memory unit 62, a Radio Frequency (RF) unit 63, adisplay unit 64 and a user interface unit 65. A physical interfaceprotocol layer is performed by the processing unit 61. The processingunit 61 provides a control plane and a user plane. The functions of thelayers may be performed by the processing unit 61. The memory unit 62 iselectrically connected to the processing unit 61 so as to store anoperating system, an application program and general files. If thedevice 60 is a UE, the display unit 64 may display a variety ofinformation and may be implemented using a known Liquid Crystal Display(LCD) or an Organic Light Emitting Diode (OLED). The user interface unit65 may be configured in combination with a known user interface such asa keypad or a touch screen. The RF unit 63 is electrically connected tothe processing unit 61 so as to transmit or receive an RF signal.

The above-mentioned embodiments of the present invention are disclosedon the basis of a data communication relationship between a base stationand a UE. In this case, the base station is used as a terminal node of anetwork via which the base station can directly communicate with the UE.Specific operations to be conducted by the base station in the presentinvention may also be conducted by an upper node of the base station asnecessary.

In other words, it will be obvious to those skilled in the art thatvarious operations for enabling the base station to communicate with theUE in a network composed of several network nodes including the basestation will be conducted by the base station or other network nodesother than the base station. The term “Base Station” may be replacedwith the term fixed station, Node-B, eNode-B (eNB), or access point asnecessary. The term “UE” of the present invention corresponds to aMobile Station (MS). The term “mobile station” may also be replaced withthe term user equipment (UE), Subscriber Station (SS), mobile subscriberstation (MSS) or Mobile Terminal as necessary.

In addition, a transmitter refers to a node for transmitting a data orvoice service and a receiver refers to a node for receiving a data orvoice service. Accordingly, in uplink transmission, a UE may be atransmitter and a base station may be a receiver. Similarly, in downlinktransmission, a UE may be a receiver and a base station may be atransmitter.

Meanwhile, as the UE of the present invention, a Personal DigitalAssistant (PDA), a cellular phone, a Personal Communication Service(PCS) phone, a Global System for Mobile (GSM) phone, a Wideband CDMA(WCDMA) phone, or a Mobile Broadband System (MBS) phone may be used. Forexample, the embodiments of the present invention can be implemented bya variety of means, for example, hardware, firmware, software, or acombination thereof.

In the case of implementing the present invention by hardware, thepresent invention can be implemented with application specificintegrated circuits (ASICs), Digital signal processors (DSPs), digitalsignal processing devices (DSPDs), programmable logic devices (PLDs),field programmable gate arrays (FPGAs), a processor, a controller, amicrocontroller, a microprocessor, etc.

If operations or functions of the present invention are implemented byfirmware or software, the present invention can be implemented in theform of a variety of formats, for example, modules, procedures,functions, etc. The software code may be stored in a memory unit so asto be executed by a processor. The memory unit may be located inside oroutside of the processor, so that it can communicate with theaforementioned processor via a variety of well-known means.

The present invention is available for a UE or a network apparatus usedin a wireless access system.

It will be apparent to those skilled in the art that variousmodifications and variations can be made in the present inventionwithout departing from the spirit or scope of the invention. Thus, it isintended that the present invention covers the modifications andvariations of this invention provided they come within the scope of theappended claims and their equivalents.

1. A method for transmitting control messages at a base station in awireless communication system, the method comprising: generating one ormore control message groups by grouping a plurality of control messagesfor at least one user equipment based on at least one criteria ofwhether or not uplink Acknowledgment/Negative Acknowledgement (ACK/NACK)channel indexes are allowed to be implicitly used in a correspondingcontrol message, whether or not a user equipment the correspondingcontrol message is intended for is able to implicitly use the uplinkACK/NACK channel indexes, a size of the corresponding control message,whether or not the corresponding control message is segmented into apredetermined number of subblocks, a Modulation and Coding Scheme (MCS)level applied to the corresponding control message, a size of thecorresponding control message after applying the MCS level, and afrequency partition in which the corresponding control message ispresent; and transmitting the one or more control message groups,wherein control messages included in each of the one or more controlmessage groups are equal in the at least one criteria, and wherein theone or more control message groups are transmitted on at least one ofreuse-1 frequency partition and power-boosted frequency partition fromamong one or more frequency partitions configured for fractionalfrequency reuse.
 2. The method according to claim 1, wherein each of theone or more control message groups occupies resource units which arelogically contiguous or physically contiguous.
 3. The method accordingto claim 1, further comprising: transmitting information about thenumber of control messages included in each of the one or more controlmessage groups or the size of each of the one or more control message tothe at least one user equipment via a non-user-specific control message.4. The method according to claim 1, wherein the one or more controlmessage groups are transmitted in a state of being aligned based on theat least one criteria.
 5. The method according to claim 1, wherein atleast one MCS level is set for each of the reuse-1 frequency partitionand the power-boosted frequency partition.
 6. A method for receivingcontrol messages at a user equipment from a base station in a wirelesscommunication system, the method comprising: receiving from the basestation one or more control message groups generated by grouping aplurality of control messages for at least one user equipment based onat least one criteria of whether or not uplink Acknowledgment/NegativeAcknowledgement (ACK/NACK) channel indexes are allowed to be implicitlyused in a corresponding control message, whether or not a user equipmentthe corresponding control message is intended for is able to implicitlyuse the uplink ACK/NACK channel indexes, a size of the correspondingcontrol message, whether or not the corresponding control message issegmented into a predetermined number of subblocks, a Modulation andCoding Scheme (MCS) level applied to the corresponding control message,a size of the corresponding control message after applying the MCSlevel, and a frequency partition in which the corresponding controlmessage is present; and decoding the one or more control message groupsbased on the at least one criteria, wherein control messages included ineach of the one or more control message groups are equal in the at leastone criteria, and wherein the one or more control message groups arereceived on at least one of reuse-1 frequency partition andpower-boosted frequency partition from among one or more frequencypartitions configured for fractional frequency reuse.
 7. The methodaccording to claim 6, wherein each of the one or more control messagegroups occupies resource units which are logically contiguous orphysically contiguous.
 8. The method according to claim 6, furthercomprising: receiving information about the number of control messagesincluded in each of the one or more control message groups or the sizeof each of the one or more control message groups from the base stationvia a non-user-specific control message.
 9. The method according toclaim 6, wherein the one or more control message groups are received ina state of being aligned based on the at least one criteria.
 10. Themethod according to claim 6, wherein at least one MCS level is set foreach of the reuse-1 frequency partition and the power-boosted frequencypartition.
 11. The method according to claim 1, wherein control messagesincluded in a same group are transmitted on a same frequency partition.12. The method according to claim 3, wherein the non-user-specificcontrol message is transmitted on one of the reuse-1 frequency partitionand the power-boosted frequency partition.
 13. The method according toclaim 1, further comprising: transmitting information indicating anumber of frequency partitions configured for the fractional frequencyreuse.
 14. The method according to claim 6, wherein control messagesincluded in a same group are received on a same frequency partition. 15.The method according to claim 8, wherein the non-user-specific controlmessage is received on one of the reuse-1 frequency partition and thepower-boosted frequency partition.
 16. The method according to claim 6,further comprising: receiving information indicating a number offrequency partitions configured for the fractional frequency reuse fromthe base station.
 17. A base station of transmitting control messages ina wireless communication system, the base station comprising: aprocessing unit configured to generate one or more control messagegroups by grouping a plurality of control messages for at least one userequipment based on at least one criteria of whether or not uplinkAcknowledgment/Negative Acknowledgement (ACK/NACK) channel indexes areallowed to be implicitly used in a corresponding control message,whether or not a user equipment the corresponding control message isintended for is able to implicitly use the uplink ACK/NACK channelindexes, a size of the corresponding control message, whether or not thecorresponding control message is segmented into a predetermined numberof subblocks, a Modulation and Coding Scheme (MCS) level applied to thecorresponding control message, a size of the corresponding controlmessage after applying the MCS level, and a frequency partition in whichthe corresponding control message is present; and a radio frequencyunit, electrically connected to the processing unit, configured totransmit the one or more control message groups, wherein controlmessages included in each of the one or more control message groups areequal in the at least one criteria, and wherein the one or more controlmessage groups are transmitted on at least one of reuse-1 frequencypartition and power-boosted frequency partition from among one or morefrequency partitions configured for fractional frequency reuse.
 18. Auser equipment of receiving control messages from a base station in awireless communication system, the user equipment comprising: a radiofrequency unit configured to receive from the base station one or morecontrol message groups generated by grouping a plurality of controlmessages for at least one user equipment based on at least one criteriaof whether or not uplink Acknowledgment/Negative Acknowledgement(ACK/NACK) channel indexes are allowed to be implicitly used in acorresponding control message, whether or not a user equipment thecorresponding control message is intended for is able to implicitly usethe uplink ACK/NACK channel indexes, a size of the corresponding controlmessage, whether or not the corresponding control message is segmentedinto a predetermined number of subblocks, a Modulation and Coding Scheme(MCS) level applied to the corresponding control message, a size of thecorresponding control message after applying the MCS level, and afrequency partition in which the corresponding control message ispresent; and a processing unit, electrically connected to the radiofrequency unit, configured to decode the one or more control messagegroups based on the at least one criteria, wherein control messagesincluded in each of the one or more control message groups are equal inthe at least one criteria, and wherein the one or more control messagegroups are received on at least one of reuse-1 frequency partition andpower-boosted frequency partition from among one or more frequencypartitions configured for fractional frequency reuse.